code: def testWalkFailure(self):
      dir_path = os.path.join(self._base_dir, "test_dir")
      # Try walking a directory that wasn't created.
      all_dirs = []
      all_subdirs = []
      all_files = []
      for w_dir, w_subdirs, w_files in gfile.walk(
          dir_path, topdown=False
      ):
          all_dirs.append(w_dir)
          all_subdirs.append(w_subdirs)
          all_files.append(w_files)
      self.assertCountEqual(all_dirs, [])
      self.assertCountEqual(all_subdirs, [])
      self.assertCountEqual(all_files, [])
  
imports: import os.path
  from tensorboard import test
  from tensorboard.compat.tensorflow_stub import compat, errors
  from tensorboard.compat.tensorflow_stub.io import gfile
label_desc: Use image node_id 17 for calling the FileIoTest obj's underlying member method code with example usage: obj.testWalkFailure() without return types